lsst.pipe.tasks.selectImages.WcsSelectImagesTask Class Reference

Inheritance diagram for lsst.pipe.tasks.selectImages.WcsSelectImagesTask:

Public Member Functions
def	runDataRef
Public Member Functions inherited from lsst.pipe.tasks.selectImages.BaseSelectImagesTask
def	run
def	runDataRef

Additional Inherited Members
Static Public Attributes inherited from lsst.pipe.tasks.selectImages.BaseSelectImagesTask
	ConfigClass = pexConfig.Config

Detailed Description

Select images using their Wcs

Definition at line 164 of file selectImages.py.

Member Function Documentation

def lsst.pipe.tasks.selectImages.WcsSelectImagesTask.runDataRef	(		self,
			dataRef,
			coordList,
			makeDataRefList = True,
			selectDataList = []
	)

Select images in the selectDataList that overlap the patch

We use the "convexHull" function in the geom package to define
polygons on the celestial sphere, and test the polygon of the
patch for overlap with the polygon of the image.

We use "convexHull" instead of generating a SphericalConvexPolygon
directly because the standard for the inputs to SphericalConvexPolygon
are pretty high and we don't want to be responsible for reaching them.
If "convexHull" is found to be too slow, we can revise this.

@param dataRef: Data reference for coadd/tempExp (with tract, patch)
@param coordList: List of Coord specifying boundary of patch
@param makeDataRefList: Construct a list of data references?
@param selectDataList: List of SelectStruct, to consider for selection

Definition at line 166 of file selectImages.py.

    def runDataRef(self, dataRef, coordList, makeDataRefList=True, selectDataList=[]):
        """Select images in the selectDataList that overlap the patch

        We use the "convexHull" function in the geom package to define
        polygons on the celestial sphere, and test the polygon of the
        patch for overlap with the polygon of the image.

        We use "convexHull" instead of generating a SphericalConvexPolygon
        directly because the standard for the inputs to SphericalConvexPolygon
        are pretty high and we don't want to be responsible for reaching them.
        If "convexHull" is found to be too slow, we can revise this.

        @param dataRef: Data reference for coadd/tempExp (with tract, patch)
        @param coordList: List of Coord specifying boundary of patch
        @param makeDataRefList: Construct a list of data references?
        @param selectDataList: List of SelectStruct, to consider for selection
        """
        from lsst.geom import convexHull

        dataRefList = []
        exposureInfoList = []

        patchVertices = [coord.getVector() for coord in coordList]
        patchPoly = convexHull(patchVertices)

        for data in selectDataList:
            dataRef = data.dataRef
            imageWcs = data.wcs
            nx,ny = data.dims

            imageBox = afwGeom.Box2D(afwGeom.Point2D(0,0), afwGeom.Extent2D(nx, ny))
            try:
                imageCorners = [imageWcs.pixelToSky(pix) for pix in imageBox.getCorners()]
            except (pexExceptions.DomainError, pexExceptions.RuntimeError) as e:
                # Protecting ourselves from awful Wcs solutions in input images
                self.log.logdebug("WCS error in testing calexp %s (%s): deselecting" % (dataRef.dataId, e))
                continue

            imagePoly = convexHull([coord.getVector() for coord in imageCorners])
            if patchPoly.intersects(imagePoly): # "intersects" also covers "contains" or "is contained by"
                self.log.info("Selecting calexp %s" % dataRef.dataId)
                dataRefList.append(dataRef)
                exposureInfoList.append(BaseExposureInfo(dataRef.dataId, imageCorners))

        return pipeBase.Struct(
            dataRefList = dataRefList if makeDataRefList else None,
            exposureInfoList = exposureInfoList,
        )

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The documentation for this class was generated from the following file:

• /home/lsstsw/stack/Linux64/pipe_tasks/11.0-2-g818369d/python/lsst/pipe/tasks/selectImages.py